Analyses of two and three pion Bose-Einstein Correlations using Coulomb wave functions

Using effective formulas we analyze the Bose-Einstein correlations (BEC) data corrected for Coulomb interactions provided by STAR Collaboration and the quasi-corrected data (raw data with acceptance correction etc) on 2\pi and 3\pi BEC by using Coulomb wave function with coherence parameter included. The corresponding magnitudes of the interaction regions turn out to be almost the same: R_{Coul}(2\pi) \simeq \frac 32R_{Coul}(3\pi). R_{Coul} means the size of interaction region obtained in terms of Coulomb wave function. This approximate relation is also confirmed by the core-halo model. Moreover, the genuine 3rd order term of BEC has also been investigated in this framework and its magnitude has been estimated both in the fully corrected data and in the quasi-corrected data.Comment: 12 pages, 5 figure

Possible formulations for three-charged particles correlations in terms of Coulomb wave functions

The recent data for Bose-Einstein Correlations (BEC) of three-charged particles obtained by NA44 Collaboration have been analysed using theoretical formula with Coulomb wave functions. It has been recently proposed by Alt et al. It turns out that there are discrepancies between these data and the respective theoretical values. To resolve this problem we seek a possibly modified theoretical formulation of this problem by introducing the degree of coherence for the exchange effect due to the BEC between two-identical bosons. As a result we obtain a modified formulation for the BEC of three-charged particles showing good agreement with the data. Moreover, we investigate physical connection between our modified formulation and the core-halo model proposed by Csorgo et al. Our study indicates that the interaction region estimated by the BEC of three-charged particles in the S + Pb collisions at 200 GeV/c per nucleon is equal to about 1.5 fm~1.8 fm.Comment: 15 pages, 7 postscript figures, with addendu

Improved Coulomb Correction Formulae for Bose-Einstein Correlations

We present improved Coulomb correction formulae for Bose-Einstein correlations including also exchange term and use them to calculate appropriate correction factors for several source functions. It is found that Coulomb correction to the exchange function in the Bose-Einstein correlations cannot be neglected.Comment: LaTex file, 8 pages, hard copies of 6 (multiple) figures available on request to [email protected] or [email protected]

A potential including Heaviside function in 1+1 dimensional hydrodynamics by Landau

In 1+1 dimensional hydrodynamics originally proposed by Landau, we derive a new potential and distribution function including Heaviside function and investigate its mathematical and physical properties. Using the original distribution derived by Landau, a distribution function found by Srivastava et al., our distribution function, and the Gaussian distribution proposed by Carruthers et al., we analyze the data of the rapidity distribution on charged pions and K mesons at RHIC energies (sqrt(s_NN) = 62.4 GeV and 200 GeV). Three distributions derived from the hydrodynamics show almost the same chi-squared values provided the CERN MINUIT is used. We know that our calculations of hadron's distribution do not strongly depend on the range of integration of fluid rapidity, contrary to that of Srivastava et al. Finally the roles of the Heaviside function in concrete analyses of data are investigated

Analyses of multiplicity distributions with \eta_c and Bose-Einstein correlations at LHC by means of generalized Glauber-Lachs formula

Using the negative binomial distribution (NBD) and the generalized Glauber-Lachs (GGL) formula, we analyze the data on charged multiplicity distributions with pseudo-rapidity cutoffs \eta_c at 0.9, 2.36, and 7 TeV by ALICE Collaboration and at 0.2, 0.54, and 0.9 TeV by UA5 Collaboration. We confirm that the KNO scaling holds among the multiplicity distributions with \eta_c = 0.5 at \sqrt{s} = 0.2\sim2.36 TeV and estimate the energy dependence of a parameter 1/k in NBD and parameters 1/k and \gamma (the ratio of the average value of the coherent hadrons to that of the chaotic hadrons) in the GGL formula. Using empirical formulae for the parameters 1/k and \gamma in the GGL formula, we predict the multiplicity distributions with \eta_c = 0.5 at 7 and 14 TeV. Data on the 2nd order Bose-Einstein correlations (BEC) at 0.9 TeV by ALICE Collaboration and 0.9 and 2.36 TeV by CMS Collaboration are also analyzed based on the GGL formula. Prediction for the 3rd order BEC at 0.9 and 2.36 TeV are presented. Moreover, the information entropy is discussed